Nissan RB30 Skyline Upgrade

Skylines Australia RB30 DOHC Guide


R32 & R33 Skyline Specific Last Update – 8th November 2007

This guide has originated from the following HUGE thread on SAU.

Please note inaccuracies may exist, so use with caution at your own risk.

Skylines Australia RB30 DOHC Guide

© Copyright 2006 Skylines Australia

Thanks to all of those who have made pictures available for use within this document which includes Cobra30

Compatible DOHC Heads

Three heads can be used for the twin cam conversion.

    • RB26DETT Head
    • RB25DE (R32) Head
  • RB25DE/T (R33) VCT Head

All three heads cc up around the 62-64cc mark.
However, please be sure to double check, there have been cases where people
have bought heads that for some reason are way off. Possibly fiddled with.

RB25’s have ALLWAYS had problems with lifters

Start up hydraulic lifter rattle is the first sign of lifter wear. It is most commonly caused by worn oil seals in the lifters. The oil leaks out over night and when you start the engine first thing in the morning it takes a little while for the oil to firstly fill up the empty lifters and then build up pressure. Replacing the lifters usually fixes this.

If the lifters are not replaced, then the wear rate increase exponentially due to the lack of oil. Eventually the lifters can’t hold the oil pressure at all and the rattle comes back at low to mid rpms. Replacing the lifters will fix this.

Eventually the lifter get so badly worn that they rattle all the time. This can lead to damaged camshaft lobes due to the excessive clearances.

So my first suggestion is to replace the lifters.

Some lifter rattle is caused by too infrequent oil changes and a resulting build up of sludge. This causes blockages in the oil flow into the lifters, hence they rattle. A few oil changes usually fix this problem, not that I think it is the case for a Skyline enthusiast, we change the oil too often for that.

Some say to put solid lifters in it which will solve the problem…
Keep in mind that a swap to solid lifters will also require a swap to camshafts designed to run with solid lifters.

lifter noise occassionally when the revs drop right down to a crazy low rpm, like 600 or less. But it clears when oil pressure returns to normal. So a lack of pressure will cause the lifters to tick abit. There might have been no problem with them originally, as in not bad enough to replace but its infact your oil pump that needs seeing to.

As some people say; if you experience hydraulic lifter tick once the motor is warm its a tell tale sign the motors on its last legs.

As a reference point the RB30’s SOHC head cc’s up around the 55 to 58cc mark.

The RB26DETT head from the R32/33 GTR bolts only requires a modification to the head stud holes.
The RB26DETT runs larger studs. All water/oil galleys line up.

b26dett head build to suit RB30

Head fits straight on as per normail RB26/30 engines,

The rb26 head having larger head studs that the rb25. You need to retap the rb30 block out to bolt the rb26 head on.

The rb26dett head, has the advantage of the front facing plenum from factory.

addition of a oil drain back from the rear of the head to the sump.

The throttle linkage mounts up very close to the same but the 25 cable is longer so use a GTR cable. Over all the 26 head is easier than the VVT head.

complete r32rb25de non vvt head with injectors coil packs, manifolds etc $500.

Fit a metal headgasket and head goes on. the problem of the exhaust manifold touching the block, so grind the manifold down rather than the block.

The issue with bonnet clearence isnt an issue with GTR’s as much due to the rb26 head.

bit of an issue with the bonnet clearance tends to hit, so i not sure either bonnet scoop or ill try adjusting it to suit.

The R32 RB25DE cylinder head requires oil flow the same as an RB20DET cylinder head. The questions are still the oil pump flow and pressure, the rpm commonly used and the length of continuous time that rpm is used. Plus what work has been done on the oil return system. So it’s not a simple one size answer, it’s more a 3 dimensional table.

At this point it is worth expanding on the discussion of RB25 oil supply. They have 3 oil feeds, one for the VVT which overflows into the cylinder head and has its own return to the sump located on the front LHS. The other 2 are the normal RB oil feeds to the camshaft bearings.

regarding the VVT oil supply, it should always be left in place, untouched if the VVT is being used. Then selecting from the 1.0 mm 1.25 or 1.5 mm restrictors according to the usage. Refer to the table for the exact details.

Have you ever seen how much smoke half a litre of oil can make when it gets sprayed over your hot red extractors ???

The oil needs to be controlled and it has to be slown down to get to the top of the engine.

i have the problem in my rb2030 its a 20head on a 30 vlt block so i gets the hi comp but my cams are 264 8.5 and ones 9.5 i think and they blow open my valves at 5000rpm ive also been told that theres too much oil getting to the head and making it hard for my lifters to bleed off
im getting prices on valve spring to suit 10mm lift cams so this should help my problem of the valves blowing open
so if i fit the 1.5mm restrictor it should be all sweet oil wise can i just fit X2 1.5mm restrictors …?

yes its a good idea
yes its been done plenty of times before
and there are 100’s upon 100’s of motors running around like this that have been fine for years
Looks like Sydneykid was right – the lifters were the cause of the issue.. i changed them and its much better now. Does not make noises at 3000rpm in 5th gear on cruise anymore.

I changed the cams as well – but time will tell if the noise comes back or whatever.. its till there if you rev it sometimes but its clear now that i have to go to solids.

get some cam seals and replace the timing belt

I feel less worried following sk’s advice for the hydraulic head.
It is worrying when you hear from engine building places not to mention tomei them selves recommending against blocking off one restrictor in a hydraulic head.
I think a final word from Proengines would be the clencher for myself.

My problem was I didn’t know of any one with an Rb20DET or R32 Rb25DE non vct head that had run with 1 restrictor blocked and a 1.5mm up front. The R32 Rb25DE and Rb20 heads are near identical apart from slightly larger ports and the larger combustion chamber/valves etc. So I wasn’t completely comfortable using the R33+ Rb25 VCT head as a comparison that it really did work without problems. biggrin.gif

But yes.. Still more than enough oil floating around; I’ve noticed I can now see the top of the bucket where as prior oil was constantly filled 1/4 up the base of the cam so impossible to see the top of the bucket.

I run the non-vct RB25 head.

I blocked off the rear restrictor as the Rb26’s are and run a 1.5mm restrictor up font.

Works fine no ticks, pops etc. Went from shit loads of oil everywhere over 5500rpm+ to a bone dry catch can. Still plenty of oil floating around in the cam covers. Prior on idle oil was puddled up to the base of the cam so you couldn’t see the lifter. Now u can.

In regards to the RB25 , why is the front feed blocked off and the rear feed restricted but with the other engines its the rear feed that gets blocked off and the front feed get’s the restrictor as per sydneykids table ??

It’s actually quite logical, VCT heads have 3 oil feeds, front (for the VCT), middle and rear. Since you have to run the front oil feed (otherwise the VCT won’t work) it makes sense to block off the middle feed and use the rear. It balances the flow better along the head. For a 2 oil feed head (non VCT) you want to use the oil feed closest to the oil pump, that’s the front one, and block off the rear one. Logical isn’t it?

we dont know where sydney kid comes up with his ideas but they have been proven to work time after time after time

I do the research, come up with the solution to the problem and then we test, test, test.

The oil flow mods were originally arrived at in 1999 and have been only slightly revised since, so there are 8 years of testing. They work, everytime, just follow the table.

In regards to the RB25 , why is the front feed blocked off and the rear feed restricted but with the other engines its the rear feed that gets blocked off and the front feed get’s the restrictor

I have a concern with the std restrictors that i pulled out of the block , i only removed the rear. The restrictor itself is of only a small orifice but its what is underneath the restrictor that i am having problems.. the restrictor is roughly 10mm long with a step down that has 3 hole in the bottom that angled into the bottom if it. Underneath that is a drian back valve or what looks like to be .

Do you remove the drain back valve aswell or just the restrictor??
If i was to but the restrictor with the valve left in place then once oil pressure reaches the valve then the valve would be shut on the bottom side of the restrictor (tomei 1.5 restrictor) that i am installing and would not let any oil up to the head . i would draw a diagram but it a bit hard to manage.. I have never seen a restrictor like this before and i am very concerned.

Kyle. I can answer that. You need to be worried about the amount of oil going into the upper area of the head and not the drainback, so just do the upper restrictors as per the guide.
i thought i’d add to this thread that with my carbon fibre bonnet, it fouled on the front of the motor. Cant drop the engine down either caus there’s only ~10mm clearance between the cross member and the axles.

One minor modification I did to expediate things down the track was to put a an extra join in the drain back line close to the head but accessible enough to get at.
Reason being The first time i lifted the head for a valve upgrade it was a total pain in the arse trying to lift the head off the arp studs as the hose wasnt long enough and it is nigh impossible to get to the back of the head to disconnect it.
Doing a cam upgrade atm and it sure bore fruit. A couple of clamps and off she comes.

I disconnect at the sump, no joins.

I am not in favour of plumbing the head oil return into the turbo oil return. The turbo rotation thrashes the oil into a foam and it fills up the hose pretty well. It might be OK on a twin turbo (as per Duncan’s application) as there is only half the oil flow in the rear turbo oil retrun. But I wouldn’t do it on a single turbo application.

Using a rb25de head off a r32 on the rb30 bottom end?

An R32 RB25DE cylinder head, is the best low cost head you can use on the RB30, with no VVT to confuse the issue, it’s a straight bolt on.
The reality is there is no need for a separate thread, it’s so simple. You can use the RB30 guide, just ignore the bits about modifying for the VVT, you don’t have to worry about that. So you can use an RB30 or RB26 head gasket. Everything else, pulley positioning, head bolts etc is the same.

what can you use on the R32 rb25de head – rb20 or rb26 cams? – Use the RB25DE standard cams with adj pulleys.
You should be able to use both but if using RB26 cams you have to use solid lifters as the ramp rates are different.

The R32 RB25DE head bolts straight up to the RB30E bottom end. All water/oil galleys line up.
N/A valve springs have less tension which may cause issues when running big boost.
Cams and springs are interchangeable with RB20DET items. Valve springs identical, cams are slightly different.

The R33 RB25DE/T has variable cam timing (VCT/NVCS); this requires welding of the heads VCT oil feed.
The head still requires oil to its VCT, you will have to tap in to the oil galley and run an oil feed to it. The most common
used feed is T’ing into the oil pressure sender feed.

Compare the pictures below to gain an understanding of how the head needs to be modified.

RB25DET VCT Bottom End RB30E Bottom End No-VCT oil galley

IF ITS A RB25 WITH VCT . leave front feed , block middle and restrict rear feed ..

VCT heads have 3 oil feeds, front (for the VCT), middle and rear. Since you have to run the front oil feed (otherwise the VCT won’t work) it makes sense to block off the middle feed and use the rear. It balances the flow better along the head.

For a 2 oil feed head (non VCT) you want to use the oil feed closest to the oil pump, that’s the front one, and block off the rear one. Logical isn’t it?

To solve the VCT oil feed problem you can remove the VVT solinoid and drill straight down the vvt oil feed galery through a brass plug and into the cavity which houses the VCT solinoid, the oil gallery on the block side of the head has been plugged with alloy expoxy putty ,when heated it expands and contracts at the same rate as alluminum which is very important!!

The R33 RB25 also requires you to plumb in an external head oil return, you can T in to the turbo drain.

The RB20DE/T has smaller ports and much smaller valves to the RB25 & 26 heads.
R32 RB20DET Inlet – 30mm R32 RB20DET Exhaust – 27mm
R32 RB25 Inlet – ~34mm R32 RB25 Exhaust – 29mm

R32 RB25 head uses the RB20DET style ports but larger.
The ports are still not ‘as’ large as the R33 RB25 or RB26 heads.
Slightly smaller ports – I haven’t been able to pick any performance downsides apart from the lack of VCT.
The ‘slightly’ smaller ports should not put you off this head.
This head is recommended for use in an R32 for ease of installation and compatibility with existing sensors & plugs.
This head uses hydraulic lifters.

R33 RB25 & RB26 heads use the same style inlet ports with the same or very similar measurements.
Use one of these two heads if you are putting the rb30det in to a R33 for ease of installation.
This head uses hydraulic lifters.

R34 RB25 heads bolt up fine; The R34 head cc’s up at 50-51cc’s
They utilize solid cams so use a bucket on shim setup. No hydraulic lifters.

The hydraulic heads can only support cams with approximately ~9mm lift before they require machining of the buckets
for clearance.

With the stock bonnet the top cam belt cover fouls the bonnet support beams.

Both GTR and GTS4.

lower the rb30/26 so the bonnet closes in a r32 gtr spaced the xmember or modified the engine mounts the cefiro rwd cross members mount/position the motor lower.

Quite possible its the same for the cefiro 4wd crossmembers. Chances of finding a 4wd cefiro cross member is pretty slim, and even then it may not bolt up.

the engine mounts from a LD28 powered laurel or R31 skyline station wagon, because of the deck height on the block the engine mounts are shorter,

the Rb30 was a australian only model in the r30, r 31 skylines and the last of nissan’s 3l stocks were sold to GMH to power the 1987 holden commodore as this was a cheaper option then trying to engineer a new motor to come in under australia’s exhaust emmisions laws as the 202 would never pass.

the patrol runs a live front axle this block could be used aswell as that from a vl or early skyline

3l gxe nissan station wagon for example.

the only major difference between the blocks of that era are the deck hieght and stroke,

Use the rb30 block and crankshaft from a vl, to replace the damaged 26 block from a gtr

get the block honed and faces machined, the crank machined and balanced, oversized bearings, new rods and pistons.

everything mostly is a straight swap, the sump, pick up , etc.

there is only so far you can lower it before the sump hits the cross-member, particularly once the 10mm 4WD adaptor plate is in there too..…Build/Diff2.jpg…0Build/Diff.jpg

Head Gasket

Personal preference.
Tried and proven is to O-ring the block and use a standard Nissan RB26 or 30 OEM head gasket.
I personally used and re-used (with a spray of Hylomar) a COMETIC multilayer head gasket.
Trust Head gaskets are excellent.
The RB30 uses the same head gasket as the RB26, an RB25 gasket can also be used.

Inlet Manifold and Plenum

R32/R33 RB25 plenums and inlet manifolds are not interchangeable.
The R32 RB20DET plenum bolts on to the R32 RB25 Inlet manifold.

R32 RB25 & RB26 heads run top feed injectors.
R33 heads run side feed injectors.
The R33 RB25 & GTR ports are slightly larger than the R32 RB25’s.

For comparisons sake, a picture of an RB20DET Inlet manifold with a R32
RB25DE gasket over the top. Note the port size difference.

Exhaust Manifold

R32 RB20/25, R33 RB25 have the same exhaust manifold bolt up. They
are interchangeable.
RB26 exhaust manifolds utilize a different bolt up pattern.

In order to bolt up the exhaust manifold of your choice you must grind
down the water galleys protruding lumps that run from the front to the rear
of the block.
They must be removed as they foul the exhaust manifold.

Short Motor

Be sure to select a short motor that has provision for the turbos oil
feed/return, water return and has both lower tensioner locations machined
flat, some do not have the machined area to mount the tensioner.
Yellow highlights vertical to one another are the oil feed and return.
The Yellow highlight towards the rear of the block is the water return.
Water feed is provided from a hose/steel pipe assembly that feeds from
the opposite side of the block.
Should the block lack water/oil provision it is possible to drill and tap.

For a street driven motor with a twin cam oil pump use the follow head oil
RB25 Head – Blocked rear , 1.5mm front.
RB26 Heads – Blocked rear, 1.25 to 1.5mm front.
Consider slightly restricting both RB25 and RB26 down to 1.1-1.2 should
the car see a LOT of track work with an N1 oil pump.
Use the RB20/25/26’s oil dip stick & holder as the RB30’s is not long enough to clear the DOHC inlet manifold.

You will have to use the RB20/RB25 block heater hose attachments accordingly. They are situated on the inlet side of the motor at the front where the thermostat resides and towards the back of the motor roughly where cylinders 5 & 6 reside.


Grind off the RB20/25/26 fins towards the back of the sump, the rb30 crank and rods have a longer throw and will foul. The RB30 sump has no clearance issues in the R32/R33 Skylines.

* Sump adaption and oil pick up.
1) Sump/Diff Adapter: There are people offering these but they take alot of work to fit/line up. Chunks of the block on the diff side of the sump ie webbing needs to be removed to clear the studs from the sump.

3) Oil Pickup, im sure there are a few methods but due to the oil pickup on the RB30 being too far back this needs to be blocked and then be tapped into from the outside of the block, the pickup on my engine is boxed and mounted to the base of the sump with a line running to the turbo side of the engine/sump. this is then connected to the oil pickup tapped from the outside with an inline filter.

I am still wondering about the SUMP adaptor, cant u just use the sump from the GTR/GTS4 on the rb30? U might have to modify it a little? Also is it ok to use a VL turbo headgasket with the 25de head? If not will an rb25det metal headgas

I already mentioned in this thread who makes the sump adapters.
yes you can use the RB30 gasket.
you can buy a VRS gasket kit which has all the gaskets for everything.

The adapter plate allows you to bolt the rb26 sump to the rb30 block. It is CAD designed to match the rb30 block to the wider 4wd sump. However there are other mods that have to be done besides just the adapter.
After that you will have to fabricate an external oil pickup due to the different pickup locations for a rwd rb series engine and a 4wd engine. You will also need to lastly modify the studs on the cv side of the sump to 2 long bolts, and also die grind or mill flat a part of the rb30 block to allow bolts instead of the studs on the diff side. This all sounds hard but i provide detailed instructions on how i did it and how you can do it, and if you are mechanical you can do alot yourself, I have done around 6 know and have sold many plates. This aside i sell the bare plates laser cut from cadium plated mild steel for $450, and if you got the rest done at a workshop it would cost no more that $4-600 in labour. So total cost is around the 1-1.2g mark, which is very competative considering RIPS will not do the job without selling you a built bottom end for $3800, and NIZPRO and AVO will not do it with out your own motor and sump sent to them and they charge $4200, theres is slightly different but I also offer different versions of tha adapter, however I am not bagging these workshops they do good work, but if you are a DIY’er then my setup is perfect for saving some money and getting involved.

If you have anymore questions please dont be afraid to ask. But i don’t really want to give out pics and detailed instructions just yet when it took me so many r and d hours to work it out for myself, like i said the other guys that do the conversions wont even sell the plate seperate cause they dont want to give away secrets!!! But like i said if you have questions about the process of fitment please dont hesitate. The plate i sell is straight forword and guys out there could make one themselves but it takes time to get spot on, and most people would rather buy soemthing they know has worked ad yeah I am not in this to make money so i basically sell the plates for what they cost me.

Cheers,My 25/30 motor is finally finished and there seems to be one thing i have overlooked, it says to grind down the webbing in the sump on the rb26 sump, since i am using a 10mm sump adptor plate will i still need to grind the webbing down?? I need to know asap as the whole motor is finished and i want to make sure the rods arent gonna hit on the bottom of the sump??

Ive never had to grind any webbing on the sump itself. I assume you mean for the webbing to clear the cross member? IF so you dont need to it doesnt touch!!
rb20/25 sumps have webbing towards the rear of the them which has to be grinded down otherwise rod cap will hit, rb26 sumps dont have webbing so dont have this problem! What the hell do i do with the gearbox since the top 4 bolts line up but the bottom 4 dont any ideas??? Thinking of just using the top 4 and leaving the bottom ones out

Have any of the guys who have done this conversion come across a problem where the bottom bell housing bolts dont line up with the holes in the bottom of the sump due to the adapter plate? I saw this on another forum where the guy made his on plate

I am going to be putting my RB26/30 engine into my gtr soon and would like to know if this is an issue


Yes, what we did with mine was to attach the gearbox to the block and re-drill into the sump extension, either that or just bolt up the top bolts dont worry about the bottom ones

So were exactly did you drill the holes into for the bottom gearbox mounts?

All you have to do is bolt your gearbox on then drill through in the sump extension, the bottom 4 bolt holes this will make new bolt holes for the bottom 4 then stick a thread in them and your biggrin.gif. We used the vl gearbox which we figured out is different to the Gtr one after as the bolt holes didnt line up, doesnt matter if it comes to it just bolt the top ones up, dont worry about the bottom ones

on. What issues have you found that are created by the extra deck height? Dump pipe length springs to mind as a ‘must do’ but what else – 38mm is enough to interefere with a/c lines, ps pump lines, rad hoses, harnesses, earth straps etc. Would be great to know how you’ve overcome these.


a/c lines = not a problem, the A/C compressor is in the same place

ps pump lines = not a problem, the power steering pump is in the same place

rad hoses = not a problem, the standard hoses fit just fine

harnesses = the engine harness actually goes downwards on a RB26, so they actually fit better on the RB30

earth straps = not a problem, they bolt to the block in the same places. The only different one is the exhaust manifold to LHS inner guard. But I always use a larger capacity cable anyway, so no big deal. Plus you have to change it if you change the exhaust manifolds.

so with a 26/30 TT config engine using all of the standard bolt on parts I need to do nothing different to a normal RB26 engine r and r except lengthen the dumps and the above mentioned earth strap, and tune? i guess fmc plumbing too..but that’s ALL?

No change to the intercooler plumbing either. But I used silicone joiners, maybe they were a little longer.
As previously mentioned, you will have to redrill the lower bell housing bolts, but that’s a 5 minute job.
I didn’t lengthen the dumps either, but they weren’t standard ones.
I upgraded the sump (Performance Metalcraft) for GTR oil surge prevention.
Plus added an oil cooler, of course.
I also extended ther lower cam cover, so it met up with the standard RB26 top cover (keeps the rocks out)

just an update guys.just fitted my proengines sump adapter. what a fooking top notch bit of kit. superb, every hole lined up a little grinding a per instructions which i have to say are also fooking brilliant. you need one buy this kit..END OF SIMPLE..bernie uk..

I’ve finally got my billet girdle finished!

It has the adapter encorporated in it. This also means my 4wd adapter plates are good to go aswell

very impressive solution shane. Are they equivalent pressure on the bearings as the standard girdle? what price?

thanks duncan, it’s taken alot of hours and money to make it smile.gif

im not sure what we’ll torque the studs to at this point, thats something i’ve gota talk to mick about. would u reckon giving more clamping pressure on the bearings a good or bad idea? or would u say try and get near to std specs as possible.

it uses rb26 headstuds as the mainstuds aswell (couldnt find an M11 ARP the right length)

Price is $2000 including all nuts/bolts & a 3mm MS template to tap/recess the block

hey shane what would you charge for a adapter like that?

for the girdle? with it fitted into a block thats been machined to suit, youd be looking around the 3k mark (including main studs)

i’ve got my machinist (different one to who machined the girdle in the pics above) quoting up on it so wont know definate prices til i hear back from him

also i would prefer to sell the whole block/crank/billet girdle as a whole machined to suit, rather than the girdle by itself, as there is ALOT of intrikit (sp) machining and measuring to be done to get it to fit properly

P.S im now getting the adapters done on the cnc out of alloy, so thats why i ahvnt gotten back to you about them yet, next week i will know pricing om them

I have also just received one of daniels sump adaptors nice piece of work! Now all i will be left to do next is modify the bottom end to suit the 4wd and relocate the oil pickup etc does anyone sell these already done??


RB30ET Pistons ~7:1 CR. Too low, you will loose response and fuel economy. RB30E Pistons ~8.2:1 CR. Nice, 8.5:1 to 9:1 is preferred depending on fuel quality.

The RB25/26 spec pistons have a smaller deck height vs. RB30 pistons.
The piston will sit lower in the bore when at TDC. Deck the block to compensate. Always measure first!

CP make a nice RB30 Flat top piston suitable, it runs a 1.280” compression height, deck the block 0.020” to achieve a
zero deck clearance, run a 0.040” head gasket all to achieve a nice 8.2-8.3:1 comp ratio with a nice tight quench that
aids low/mid range power and improves fuel economy. They have recently released a piston to achieve a 9:1 ratio.

RB30 PistonsForged piston selection Vs compression

4) Compression ratio on mine is close to 9.0:1, by using positive RB26 CP pistons.

Just make sure no one sells you RB26 pistons as RB30 twin cam pistons as many companys do.

Use a piston made for the job like CP and Arias. The correct piston is avalible so why not use them

RB26 piston sits way down the bore and thats incorrect because its supposed to end its stroke flush with the top of the block. Otherwise compression, squish etc are all off..

Ross is one piston thats sold as an RB30-26 piston that is really an RB26 piston and its a long way from the right piston for the job,5mm or so down the bore.

RB30 etc crank oil pump drive extensions are cheap in WA now, cheapest in the country and done very well.

Cubes and i are using Wiseco rb25det pistons in our rb30det. They decked the block (20 thou?), and added a 3 layer metal head gasket, and compression works out to around 9:1 if Cubes’ calculations are spot on

Oil squirters are overrated. Ceramic coat the pistons etc if you run cast ones, or just run forgies and dont worry about it

What rings are you going to look at this time around? King have a good rep with the rb30’s.
However its a must they run the HP bimetal bearings as trimetals are crap in a performance application.

Its got 350rwhp… so the stock bottom end was no up to the task ?? I am being forced to upgrade to forgies so this does not happen in the future but i dont know why i need forgies… stock should be enough but in this case it could not handle my style of driving

A lot of the rb30 blokes are running precision hypereutectic pistons with either nissan or king bearings, some run acl.

Apparently the acll hypereutectic pistons are shiet. tongue.gif

There’s a bloke here on sau s3girl, he’s been pushing 373rwkw through his rb30 running std bearings, bolts and hypereutectic pistons with a GT40 bolted on the side for quite some time, I believe rev cut is around 7k.

I just the ACL Race series pistons in my car for the RB30DET with 25 head and they are good. they are acually a MAHLE piston imported from the usa by ACL because it costs too much to make forgies in australia. I think MAHLE are the same brand as ROSS ?

my compression test came up at 120 in all cyl so its a little lower then before but good for high boost =)

i used the precision motorsport conrods in my engine as well which they all come out of the same factory in china (scat eagle rah rah) they do well for what they are (can handle 700rwhp) without any issues

Precision H-Beam Forged Rods – Nissan Skyline RB30/ Holden VL Commodore (set of 6) $1,150.00AUD (inc GST)
$1,045.45AUD(ex GST)
$1,020.00AUD (inc GST)
$927.27AUD(ex GST)

Forged Conrods are a must for a bullet proof rebuild on your turbocharged engine. This allows the stress to be taken off the bottom end under high rpm and high boost. Of course forged pistons are not essential, but are highly recomended.

Precision Motorsport rods are manufactured from certified 4340 steel, vacuum degassed to remove impurities, and multistage heat treated. Each forging is X-rayed, and shot peened to relieve stress, and all surfaces are 100% machined.

H-Beam Connecting Rods Feature:

NEW 4340 Certified Forged Steel Rod
ARP 5/16 2000 capscrew bolts standard
Silcone Bronze bushings for floating pins
Precision alignment sleeves positively locate the rod cap, eliminating cap walk
Packaged in weight matched sets end to end +/- 1 gram
Rated for upto 750 horsepower (Same as the limit of the factory RB30 Crankshaft)

My RB25 is for circuit racing only. Just turned it into a 5 cylinder with number one creating a new hole in the block. I need to go the dry sump way but cannot find any information on pan set up or specs. Can any body shed any light on the subject.
The wet sump ran wings, baffles, trap doors whilst the top end has enlarged breather holes going to two catch cans and a large bore line back to the sump including a holly red pump to drain oil back into the sump from the catch can.

You can of course leave your sump the way it is and simply plumb in 2 dash 8 fittings for the scavenge pumps. One moire at the rear of the cylinder for the 3rd scavenge stage and its done.

Most of us have used the air con compressor bracket on the LHS of the engine as a mountimg point for a 4 stage pump, like the Peterson 03-4201 Left Side, Twin Blade, Std Pressure

This is a 3 stage RHS, I can’t find my picture of a 4 stage LHS, but it give you the idea

The crank spins clockwise, so the best place for the sump valley is on the RHS of the engine, with the scavenge lines going under the sump from the pump. Chevy dry sump pans utilise the same logic

If you are building a rb30/26, but want to keep the standard pistons, the valves will clear.

The RB30 conrods (and all RB rods for that matter) are pretty strong. We regularly see 500 bhp RB30’s with standard rods in them last a fair while. It really depends on the quality of the tuning, the bearings and the integrity of the oil supply. Better quality rods bolts also assist.Plus using a lighter, forged piston helps the rods last longer.

How many standard cars have forged pistons as standard? I can think of over 40 without any problems. None of them display the issues you refer to. Most of them have at least 100,000 kilometre warranties from their manufacturers.

The real issue is not how the piston is made, but what tolerances the engine is set up with and how the thermal expansion is handled by the block, cylinder liners and ancillaries like radiator, thermostat and water pump. You would also need to consider support mechanisms like ceramic-coated piston crowns and teflon coated skirts.

The piston manufacturers recommendations and data sheets are of considerable benefit when determining tolerances.

he standard Nissan main bearings are perfectly OK, used in engines up to 750 bhp.
The big end bearings are not so good, we use Nizmo big end bearings as the standard ones don’t seem to be able to handle the combustion pressures.

It doesn’t matter what oil pump we use, they always show stress on the top shell after as little as 3,000 kilometres.

RB30ET pistons with a RB25DE head would give a very low compresion ratio, about 7 to 1 if I remember rightly.
That’s gunna make a poor response, slow to build boost, dog of an engine.

This is becasue the RB25 cylinder head has way bigger combustion chambers that the RB30 head. RB30E psitons will give 8.3 to 1 which is still not perfect, but much better than 7.

Don’t machine the crank, it is nitrided, just balance it.

what if i used non turbo pistons with better rings?

also i thought using the non turbo rb25 head would make more compression than a turbo rb25 head? or is it the same?actually i would be the same wouldnt it, also what would be the best compression ratio? around the 9’s? and using the t04 is cheap thats why lol i dont wanna go spending $2000 on turbo, well if i can get away with r32 ecu then maybe spend more money on turbo but who know,i want to build the bottom end first then make decisions from there. But help on the compression side would be good what about a slight machine the top of the block?

Can’t deck the block as the pistons have a dish in them and you would have to machine the pistons as well. This would weaken the ring lands.

I prefer to use around 9 to 1, makes a much more responsive engine. Plus, with the current generation of turbos, you don’t have to run high boost to make good power. So you don’t have to decompress an engine like you use to.

I read somewhere that factory RB26 pistons are forged, and are good for up to 550+bhp.

If there is no problem with the CR, they might be a reasonable alternative to aftermarket forgies if not chasing huge hp.

Also they have holes in the bottom for oil cooling, would they have and adverse effect on stregth if not bein cooled by the squirters?

It wouldn’t be hard to adapt the RB20/25/26 oil squirters.. Well apparently it isn’t. There is a bloke in Edwardstown that builds up rb30DET’s when I asked about the oil squirters he said he always fits oil squirters in to the RB30DET Block.


Stock rods have proved to be reliable up close to 500rwkw providing the motor is spun to no more than 7000rpm. Spoolup on SAU offers a great deal on forged rods. ~$800-$900 for a set RB30’s run a 152.7mm Rod. This gives us a nice 1.8:1 rod ratio.


The crank is nitrated from factory, providing it is in good condition, a linish is only required.
On some high km RB30 cranks the front and rear seals eat away at the crank a little, if bad enough this has to be re

The R32 RB20/25/26 and series 1 R33 RB25DET crank to oil pump engagement does not engage with the full length
of the oil pumps internal gear. Think of it as placing pressure on your rib cage with a single finger then doing the same
with your palm. With a greater surface area wear on the surface where the two gears engage is reduced.
It’s a well known issue, It is a very wise move to have a full length crank collar installed, the item costs approximately
$100 or $350 installed
A JUN crank collar can also be purchased for a greater cost..
Both crank collars are universal and suit ALL oil pumps.
ALL RB twin cam oil pumps will benefit with the use of a full length oil pump drive collar.

Engine Bearings

The Genuine Nissan Bearings are good but there is better available.
King Performance bearings, Clevite and ACL are all excellent.
Ensure you have plenty of oil flow, pressure, suitable clearances and you will have a strong reliable motor.

Oil Pump

Many have had success using the RB30ET oil pump.
It is best to use an oil pump from a twin cam motor as these provide more flow and

All RB oil pumps are interchangeable.
I’ll stress again. The RB pumps do have a reliability issue and crack if used at
7000rpm+ and high km’s without a crank collar.

Ensure you use lock tight on the bolts when assembling the oil pump as they are known to rattle loose causing a gradual loss of oil pressure.

Yep, it’s all RB’s, the block, oil feed and return systems were designed for ~6,000 rpm occasionally. Circuit, drift and drag means higher than that rpm and for longer periods of time.

Circuit, drag or drift RB’s with excess oil in the cylinder head, not enough oil in the sump, oil in the catch can, wet sump, oil surge, lack of oil, big end bearing failure etc

I get about 10 X PM’s a week from guys with this problem, I have posted up what is required many, many times. But still the guys want a solution after they have assembled the engine, it is in the car and they now have a problem. Well the bad news is there isn’t one solution. The answer is to do all of the steps when you are assembling the engine and then you won’t have a problem. There is no one magic, off the shelf solution. Buying a brand name restrictor, sticking it in the block and expecting that to fix the problem on its own is naive at best. Similarly fitting a baffle in the cam covers may overcome the catch can problem but it will still leave the others. whistling.gif

On the circuit race cars we take a 5 step approach in controlling the amount of oil that is trapped in the cylinder head and/or blown into the catch can; thumbsup.gif
1.Block off one oil feed in the block (RB26’s have this standard)
2.Fit an appropriately sized restrictor to the other feed. The size of the oil pump is one of the determinates for the size of the restrictor, ie; a high flow, high pressure pump needs a smaller restrictor. Constant higher RPM needs a smaller restrictor etc.
3. Fit an external oil return from the rear of the cylinder head to the sump
4. Drill out the oil return galleries in the head and block
5. Machine around the oil return galleries to facilitate access for the oil

It seems to me that many guys do #2, and some maybe #1. If you haven’t done #3, #4 or #5, then please remember that they are cylinder head off jobs. Drill out the oil return galleries in the head and block is pretty much self explanatory. As is machining (die grinder) around the oil return galleries to facilitate access for the oil to the return bgalleries. The external oil return fits to the rear of the cylinder head at the Y, there is a welsh plug there that you can remove and replace with a fitting. Then braided line to another fitting in the top of the LHS sump wing if you have one. If you don’t, then you should for circuit and drift work.For the oil return on an rb26, can you add a fitting to the standard sump or does it need to be a custom sump? Thanx

Piston Oil Squirters

Oil squirters are used in the imported turbo Skylines to help remove heat from the piston crown which improves reliability.

Ceramic coating the tops of the pistons works well but can create hotspots elsewhere. If ceramic coating, ceramic coat the whole combustion chamber.

Adapting the oil squirters to the RB30 block is possible; however the main bearing oil gallery is in a slightly different position to those in an RB20/25/26. Machining is required to make them fit.

With regards to the RB30 or 31 bottom ends how do you go about putting the oil squirters in?

Also, isn’t there a problem with harmonics?

1. Block mounted oil squirters can be fitted, but it is a bustard of a job and not all RB30 blocks are suitable. For temperature control, ceramic coating the piston crowns and oil retention coating the piston skirts works very effectively and costs less.

2. Grossly overrated, same bore and stroke as a 2JZ, never hear about harmonics in them. Proper balancing goes a long way and the block strength added by the 4wd sump adaptor helps as well.

The castings are slightly different, the oil gallery that the squirters have to be tapped into has variances in its diameter and the wall thickness varies as a result. I have found no common ground, S1 blocks are not better (thicker/more consistent) than S2 blocks, N/A blocks are no worse than turbo blocks, Skyline blocks are no better than Commondoor blocks. Basically you buy 10 X RB30’s and start measuring, only 1 or 2 will be suitable. It is still a bustard of a job to do, takes hours and a special jig, so very costly. Even then the result is not guaranteed.

My own RB31DET has oil squirters and no I am not pullng it out of the car to take photos. It doesn’t look any different to RB20/25/26 oil squirters anyway, there just isn’t the raised section where they bolt on.

We have built lots of RB30’s without block mounted oil squirters, they show no signs of additional wear or damage when they are serviced. My suggestion, forget block mounted oil squirters in RB30’s, ceramic coat the piston crowns, oil retention coat the skirts and move on.

The bottom of a RB 2wd block looks nothing like the bottom of an RB 4wd block. The 4wd block is much wider, has many more and much larger diameter bolt holes. As you would expect to hold up a big diff, drive shafts and large cv joints for the front drive.

I am using two 0.75mm ( 30 thou ) restrictors on my RB30 with RB25 NEO head ( solid lifters ). I have done approx 20 power runs on a dyno to 8000rpm and there isnt a drop of oil in my catch can – let alone all the street floggings its got. I also have a mate running a RB30 with RB26 head who is making 490 rwhp who is using the same size restrictors and has been driving his car for at least 6 months now and has no oil problems, his rev limiter is set at 8200.
Both are street cars, not circuit or drag. We modified the oil drain back holes with some die grinding, just to open them up a bit for increased flow and apart from the oil restrictors there are no other modifications. He is running a std RB26 pump where as mine is running a JUN pump.

etting the oil piump collar is is a 100% must do. especially when using the N1 pump as there has been MANY MANY failures.

I did the oil pump collar on my engine and i still used the standard oil pump which is not prone to cracking and breaking like the N1 pumps are.

so the answer is.. YES. please do the crank collar. if you dont your crazy.NP mate. it does not require welding but it will require your machineist to machine down the crank and fit it correctly. its not a easy job and you have to have the crank out of the engine to do the task.

The RIPPS RB30 comes with a custom sump extension as well as 4wd adapter, so I wouldnt have any issues with that. It also comes with forged pistons and rods.

So the only modifications I would need to do would be:

Re-Tap for RB26 head studs as they are larger
Redrill the lower bell housing bolts
and possibly extend lower cam cover? (not 100% sure what you mean)

I do have a few questions as I dont know if they pertain just to the 25/30 or also to the 26/30.

Do RB26 Nismo Motor mounts work on the RB30? Or do you need RB30 specific motor mounts?

Do I need to worry about the oil squirters with forged pistons and rods?

Also how about the oil and water pickup lines. Do I have to redrill holes in order to use the RB26 head?

It seems to be a pretty straightforward thing to do the 26/30 conversion in a GTR, however I want to make sure I have all my ducks in a row for when my motor gets here.
If RIPS is doing the bottom end, let him be your guide. He has the experience and also if anything goes wrong you both start from a known point.

He can make all the lines etc for you if you ask him, and will most likely tap the block for the 12mm head studs before he puts the bottom end together. He will also be able to redrill the correct bell housing holes etc for you. In fact, if he is doing the bottom end I’d get him to provide as much ‘plug and play’stuff as you can afford. RIPS can pretty much make anything you need as he has jigs/half cuts etc for a whole bunch of combinations, it’s not cheap but his fabrication is A1 and he knows what works. Removes the potential for ‘head scratching’.

The oil and water lines don’t need redrilling but you’ll need to account for the 38mm higher deck. Again, RIPS can make the stuff up and knows what you needed.

Block preperation after taking all the dags off and polishing everything up, send the block off to get machined/cleaned.

Now my particuler RB30 Block is on its second rebuild. Because the boreing process is increased in .10 increments & my motor has allready been oversized by .10 so this means that i will take it out a further .10 bringing it to a total of a .20 oversize over stock. (good idear to check this before you buy a RB30 Block and bring it home, as my motor will only be good for another rebuild, before you start running into heating problems, and issues with distorting cylinders). will this total bore of .20 bring my total engine displacement out to 3200ISH CC?

Also while your motor is at (INSERT YOUR MOTOR MACHINIST HERE) its a good idear to have all the centre jernals given a light hone & re-lined so that the crank sits dead straight. This prevents un-even wear on your bearings. So this is what i have at the moment:

(Guide FYI)
Machine & hone out on all 6 cylinders: $150 / $25 per cylinder.
Balancing of crank : ??? iam guessing around $70-$100
Acid clean:$70 ISH
Alligment/Machining of centre jernals: $100 ISH

So this is basicly everything you need for the BLOCK!
Note: to balance the crank or the centre jernals, i think you need pressure plate/flywheel & harmonic balancer that your going to use. so that they can balance it properly.

Water pump & Thermostat

All GTR, R32 RB20/25 & VL/R31 RB30 water pumps and thermostats are interchangeable.

R33 RB25 water pump have a slightly different bolt up pattern. The RB30E aftermarket water pump will set you back $70 to $90. The RB26 N1 water pump is anti-cavitation and flows more.

Genuine thermostats feel and look much better quality than aftermarket items. You will be required to use the RB20/25 thermostat housing to allow for stock hose positioning.


All of the RB20, 25 & 26 Flywheels are interchangeable.


The only modification to bolt up ancillaries is the Power steering bracket. The RB20/25/26 the top power steer bracket mount bolts up to the head.

Due to the extra deck height the rb30 has the top power steer bracket mount bolt up to the block. You will be required to grind the lug flat so the bracket is able to sit flat on the block. The R31 Skyline power steer bracket looks identical to the modified R32 power steering bracket. Look in to it.

Knock Sensors

The GTST knock sensors are the same knock sensor type as the RB30’s run. The RB26 knock sensors are a different type that utilizes a different bolt size; sleaving of the original block boss’s are required OR you can drill/tap the 2 blank boss’s above the std boss’s.


Use the corresponding ECU to the head you are using. It simplifies wiring, injector and sensor compatibility.
The R32 ECU’s can be re-mapped; AP Engineering PowerFC’s are also available.
Ensure the ECU you select supports the following features:

    • Closed Loop – Fuel economy & Emissions
    • Knock Sensor – Safety
    • Sequential Injection – Fuel economy & higher average power
  • 6 ignition drivers – Doesn’t overwork your coils

The R33 & R32 ECU’s will run the RB30DET with no problems for the run-in period.
However, do be sure to have it checked on a dyno just to make sure there are no issues elsewhere.


The standard RB20/RB25DET AFM’s are 80mm
The Z32 AFM (80mm) or the VH41/Q45 AFM (90mm).
The Z32 AFM supports a little over 300rwkw with the Q45 AFM supporting up to 350rwkw.


The R32 RB20/25 (260cc) and RB26 (440cc) injectors are top feed. The RB26’s run low imp. injectors the rb20/25 high imp. Injectors.

The R33 RB25DE/T run side feed injectors. The Turbo injectors are 370cc items.


A minimum of a GT30R or equivalent is required for the motor to rev nicely to 6500-7000rpm on the standard cams.

When using the stock turbo you will be required to use a longer piece of oil resistant hose for the oil drain pipe, you will also be required to bend and stretch the oil and water lines to meet with the turbo. It’s not a problem.

RB30/26 or 30/25 conversions into R32’s Turbo and manifold.

25/10 is way too small On boost its useless, just wheelspin.

If you are building a rb25/30 and want 450-500hp at the wheels a garrett GT35R 0.82 exhaust housing is the perfect choice for that hp target. you ‘could’ mount it on a low mount manifold, however you are better off using a properly made hi-mount manifold like a 6boost to gain the optimium performance. Also hi-mounts are 10x easier to work on
Could also use a custom adaptor plate to standard manifold which runs an external wastegate along with custom dump pipe

a custom adaptor plate can be used on the standard exhaust manifold to mount a bigger GT3540 turbo and a Tial 44 external wastegate.

30/25 conversion into my GTS4 and want to run a T04z 800hp turbo, but am concerned as to weather it will fit under the bonnet, or be that close it will burn the paint off it.

Another option is twin GTRS’s and a custom modified manifold based on chopped up GTR manifolds and a RB25 manifold.

. my rb26/30 has now done 2500 miles no problem whatsoever, but is under turbo,ed.
specs is as follow,

rb30 block decked bored to 86.5mm
spool rods, cp forged slugs.
acl bearings,arp bolts everywhere.
trust sump
1000cc injectors, twin in tank tomei fuel pumps.
hks drag 4″ intercooler..
1.0 tomei headgasket.
jun stage one cams 264/272 9.7mm lift.

full extreme turbomanfolds kit using a gt35r 1.06 rear 4″ dump
car made 680bhp 645lbs @ 5500rpm but drops off after 6500rpm,s

pm,ed leigh ref replacement kit as i have a buyer for mine.
thinking of going t4 flange and twin scroll.

leigh suggested gt4088r or 4294r
not sure what rears to use on either, or spooling times on either too?.

looking for 750-850 bhp @ the fly..with a good spool

——————– i run one mate in a 33gtr . homebuilt done 5500 miles in it now no probs,. search my name for threads. currently its running 2.5 bar boost on a gt4094r blower about 800bhp @ the fly..bernie uk.
ps i use the spool rods/cp piston package, proengines sump adapter, acl bearing, n1 oil/water pumps. 6 boost turbine kit, os giken quad plate clutch. car runs 8 bar oil pressure cold @ idle 5 bar hot @ idle. and it goes like a train.
here,s my old turbo spec sheet.

great result witht he GT4094R rockabliiy!

mild 2.6 – modded 2.6 – 3.0 with low mounts – 3.0 with neo head with medium-big single

So my question to you is: Why did you end up going for the GT4094R instead of the GT40R (GT4088R)?
And are you happy with the response compared to ur old GT35R?

hi guys, the gt35r was good spooled hard around 3500rpm with a 1.06 rear, it was a single t3 entry and looked like if was fading off towards 6500-6800rpms, talked to kyle @ 6 boost and to be honest it was a toss up between the 4088r and the 4094r. but there is no comparison, the gt4094r with a .96rear is a fooking animal.t4 twin scroll, full boost thats 2.5 bar by 5300, 1 bar by 3300. and it comes on so hard at 70mph in 3rd when you plant it all 4 wheel wheelspin.
fuel is pulp 98ron shell v-power. knock 35-45
power comes on strong from 3200rpm any gear. right through to 8k.

torque was 620lbs @ the fly no graph, bhp was 610 @ the hubs/wheels. and dyno chart below, haven,t 1/4 mile it yet. still on std gtr box which it will break if i do, mainly use the car for track work and road .

on the graph car ran 1.85bar boost but the wastgate spring was to weak, since then we haved upped the spring and boost to 2.6 bar, will be intersting to dyno this year.

here,s a clip when it ran at anglesey north wales at 1.3bar november 08.

shifting aroung 7600-7800 but went to 8350 a couple of times, logged on the ecu,
bov,s yes twin blitz super seqentials,cant hear them over the turbo..

fuel is shell 98 ron, 1000cc,s injectors, twin entry rail,twin tomei intank pumps feeding rail at bothe ends, 10mm return to tank..

advice/pictures on how to do the fitting to the block for the rear Turbo Drain? Looking at it today its a bit of a pain. It it very close to a bolt which goes through the sump adaptor ans into the sump. This bolt has to be ground down on one side to get at the fitting properly.. On top of that, if the fitting protrudes too far its going to foul on the axle casting… (hope you are following me here…) smile.gif

The front turbo I am draining to a dash 8 fitting on top of the wing of the sump.. so that’s no prob..

for mine i just took out the std fitting in the block, went down to pirtek and got a t-piece. I then put that in the block and ran rubber hose from each drain to the t, easy! (hose has heat wrap on it too)


All of the RB gearboxes have the same bolt up pattern.
The R33 Series 1 and Series 2 gearbox’s all use a push type clutch.
The R32 RB20DET gearbox doesn’t like the 3ltr torque, I stripped third gear with only ~180rwkw.

To put things in to perspective, the rb30det making ~180rwkw was making the same amount of torque as an rb25det
making 300rwkw.
The RB25DET gearbox is known to hold up to 450-500rwkw and is fine for the RB30DET

Engine Mounts

The RB30DET block is approximately 38mm taller than any of the other RB blocks.
This causes a few fouling issues with the bonnet when used with the high RB25 stock inlet manifold/plenum.

The RB26 inlet manifold/plenum doesn’t have these issues as it sits much lower.

If you want to run the stock RB25 inlet manifold/plenum you will have to lower the engine by 15mm on the driver’s side
and 12mm on the passenger’s side.
You will then be required to remove the lower lip of the radiators shroud otherwise the fan will munch it up.
I also found it worthwhile to relieve the gearbox and centre bearing mount slightly. In an attempt to reduce driveline
angles to an absolute minimum.

One good reason to use the RB26 head.

Factory Cam Specs

This information is courtesy of Tomei’s web site. It may not be 100% correct.

VCT/NVCS, experimentation has indicated the more power you make, the lower the VCT/NVCS engagement rpm will be. This is reflected when comparing the rpm of NVCS engagement for the turbo and non-turbo engines.

The only way to find is by experimentation or through the use of a computer simulated engine dyno package such as Dyno2003 or even better and much more accurate do two dyno runs, one with the vct engaged and the other with it disengaged, where the two graphs overlap this is the perfect rpm to have the vct engaging.

Cam Belt

I positioned a tensioner above the water pump as per the pic below. Don’t worry about drilling in to the water galley
located approximately 9mm deep as you can tape up the studs thread and it won’t leak.
Ensure the studs hole is drilled and tapped square!

Courtesy of Cobra30
Due to the extra deck height of the RB30 Block you require a belt that is approximately 11 teeth longer.
A total of around 152 teeth will be needed the Dayco part number for this setup is 94407.

Courtesy of Cobra30

Using a tensioner and idler we found the timing belt tension to be greater than the factory recommended spec of

We used a second tensioner in place of the idler bearing (lower bearing) in order to bring the belt tension down to the
factory recommended spec of 20kg’s.
This gives us much more adjustment not to mention how much cheaper a new tensioner is compared to an idler.
Use the RB20/25 lower cam belt cover as the RB30 cam belt cover is slightly taller and fouls with the top tensioner.

It is possible to use the factory tensioner and idler locations however once again you will be required to use two tensioners to get the correct belt tension.

I personally do not recommend this method as the belt comes too close together.

It uses a Gates POWERGRIP GT2 p/n 1200 8MGT 30 It measures 1200mm long, 8mm pitch on teeth, 150 teeth, and 25mm wide, it was cut down from 30mm in the factory.

There is also a Bosch belt that can apparently be used – VB-T866, I have no further information on it.

There has been some reports of a harmonic effect when using the POWERGRIP belt as the tooth profile is apparently slightly different to the cam and crank gears.

When marking out the position to drill and tap the upper tensioner do be sure to dummy it up to ensure the belt and tensioners clear both the lower and upper cam belt covers.

GTR/GTS4 Special Notes

The RB30 shoehorn in to the GTR and GTS4 engine bays is a huge squeeze. Due the the 4wd the ability to lower the engine has been removed. Engine and bonnet fouling issues occur. It is imperative a GTR style low mount position inlet manifold/plenum is used. The Bonnet support structures must be slightly trimmed to clear the cam belt cover. The GTR’s standard turbo pipe that has twinturbo written on it also fouls the bonnet, the bonnet support structure in that position must also be trimmed.


How hard can I rev the RB30 safely?

As with the R32 GTR, R32 RB20DET and R33 RB25DET S1 motors they all have a small oil pump crank drive.
Excessive rev’s 7500rpm on all of these motors will eventually see a failed oil pump.
That being said the RB30 ‘harmonics’ are overrated. They rev no problems to 7500rpm, however at this rpm you most
definitely should be running a full oil pump crank drive from Jun or ProEngines and ensure the motor is well balanced.
For the ultimate reliability anything past this and you would seriously want to look at forged rods, pistons and an
aftermarket (ATI) harmonic balancer.
Do all these things and providing you have big enough cams to support the airflow and the motor will rev and be
One last thing… Back in the Bathurst days the Gibson motorsport team restricted the RB26’s to 7000rpm. Much over
this and the motor saw a much shorter life. So as with all RB’s keep rev’s to a bare minimum if you want it to last.

1. $25- Key Rings -Pewter MFR AU – PRO’s Light / small/ universal appeal? Prob OK Margins $5/$25 Vinyl Graphics Stickers MFR AU

2. $39 DVD’s Special car oriented stuff -not Movies like Fast&Furious
Light / Small Lo$ OKmargin – Universal appeal

3. $30-70 Books -specialist turbo and Subaru WRX Dist AU Light / small Lo$ Margin? – Limited appeal $99 Seat covers MFR AU
$50?100 Gear Knobs MFR AU [email protected] – special spiders set in epoxy.

4. $70-150 Air Filters UNIFILTER MFR AU
Light/ small/ first mod for most cars, mid$

5. $100+ Clear Tail lights and Headlights AU IMP/DIST

Light / small / universal appeal prob OK margin
6. WRX Custom Headlights MFR AU SLACE 0414271674 $xxx Lights -Strut Braces- Dials DIST AU 6.********$250 ea Brake Rotors -Slotted & Crossdrilled MFR AU Great product but hi$ -heavy / large/ Universal fitment Margin?
7 $1500 -2500 Intercoolers / Turbos MFR AU
PRO’s= well dev Aust made but $$$’s Large / heavy Margin maybe OK
8 $100 – 2000 Suspension components WRX MFR AU
GEN MFR AU GEN MFR AU PRO’s = well dev product ranges CON’s Heavy / large/
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10. $1000-2000 ECU’s – Car Computer Elec Fuel Control Systems
MFR AU MFR AU – mentioned in Fast&Fur. MFR AU DIST AU WRX’s =LIght weight / small / good margin maybe / Good reputation. 5 or 6 makes available mfd Au CONS Hi$


Thanks to Skylines Australia for making my RB30DET and this guide a reality.
A really big thanks to all those over at SAU, especially Christian (Prank) for spending his hard earned $$ on SAU and
Skylines Downunder who have also shared their knowledge.

Head over to the current RB30 Thread at Skylines Australia.
I am sure you will be thankful for this guide when you check out how large the thread is.

A big thaks to all those that have done the rb30det combination In the past and taken pictures, some of those I have
included in this guide